Spock: [The Horta] found humanoid appearance revolting, but she felt she could get used to it.
McCoy: Oh, she did, did she? Now tell me, did she happen to make any comment about those ears?
Spock: Not specifically, but I did get the distinct impression she found them the most attractive human characteristic of all. I didn’t have the heart to tell her that only I have—
Kirk: She really liked those ears?
Spock: Captain, the Horta is a remarkably intelligent and sensitive creature with impeccable taste.
Kirk: Because she approved of you.
Spock: Really, Captain, my modesty—
Kirk: ...Does not bear close examination, Mr. Spock. I suspect you're becoming more and more human all the time.
Spock: Captain, I see no reason to stand here and be insulted.

I love this.

Also, Data, regarding Spot (the cat) after Spot has destroyed Geordi's quarters: "Spot does not respond to verbal commands. "

A short time later: "DATA: Geordi, I have taken your suggestion regarding Spot. I have begun training her.
LAFORGE: Really?
DATA: Yes. I am studying several new techniques. I began with simple conditioned response exercises and followed with environmental enhancement. Next I plan to explore bioconditioning devices.
LAFORGE: Devices?
DATA: Such as sensor nets for behaviour modification or biofeedback motivators. Unfortunately, I have been less than successful.
LAFORGE: I've got an idea. How about a phaser? A low stun setting at just the right moment might do the trick.
DATA: Geordi. I cannot stun my cat. "